The present invention relates to light duty detergent compositions based on anionic sulfonate and/or sulfate surfactants, optionally containing nonionic surfactants, of enhanced foam stability and degreasing ability, particularly in water of less than about 70 ppm hardness, preferably 50 ppm or less and most preferably 0 pm, containing a low molecular weight organic diamine diacid salt.
Light duty detergent compositions in commercial use at the present time are usually in liquid form and are based on sodium and/or ammonium salts of anionic, sulfonated detergents with or without nonionic surfactants, which together with additives such as conventional foam boosters, provide satisfactory detergency and foaming as shown in U.S. Pat. No. 3,755,206. However, the major drawback of these detergent compositions is that their foaming and/or degreasing performance in water of hardness below about 70 ppm is very poor.
The prior art discloses the addition of magnesium and/or calcium salts to detergent compositions to improve washing performance, especially under soft water conditions, as shown by U.S. Pat. No. 2,908,651 wherein magnesium chloride or magnesium sulphate is incorporated in liquid detergent formulations containing an alkali metal or amine salt of an alkylaryl sulfonic acid and hydrotropes and by British Pat. No. 1,164,854 wherein a magnesium salt, e.g., magnesium sulfate, is added to a liquid detergent composition based on alkylbenzene sulphonate and a nonionic surfactant and/or an alkyl or alkylphenol-polyether sulfate.
The prior art discloses the use of magnesium salts of anionic surfactants as another means of obtaining improved foaming detergency performance in soft water as shown in British Pat. No. 948,383 wherein the liquid detergent compositions contain up to 30% of anionic sulfonated detergent and magnesium xylene or toluene sulfonate as solubilizer for improving the diswashing performance in soft water; French Pat. No. 1,233,047 wherein the detergent composition is based on up to 30% by weight of magnesium alkylaryl sulfonate added to a mixture of sodium or triethanolamine alkylsulfate and an alkylpolyether sulfate; Netherlands Pat. No. 7,607,160 wherein the liquid detergent composition is based on magnesium salts of a broad class of anionic sulfonated or sulfate detergents and a nonionic condensation product of ethylene oxide; and U.K. Pat. No. 2,010,893 wherein the liquid concentrated detergent composition is based on magnesium alkylbenzene sulfonate containing dialkyltetralin and an alkali metal, ammonium or amine alkyl polyether sulfate and/or a nonionic surfactant.
Also disclosed in the prior art is the use of polyamino compounds in detergent compositions as shown in U.S. Pat. No. 2,267,205 wherein N-alkylated polyamines such as N-n-C.sub.6 -C.sub.10 alkyl ethylene diamine in the form of a free base is used as an alkaline surface active agent in lieu of sulfated higher alcohol salts and the use of ethylene diamine in aqueous cleaning compositions for metals and glass as shown in U.S. Pat. Nos. 3,003,970, 3,309,321, and 3,173,876. However, none of the aforesaid patents disclose anionic surfactant based liquid detergents containing the diacid salts of a low molecular weight organic diamine.
In U.S. Pat. No. 3,935,129, the problem of providing a composition capable of cleaning in water of any hardness is also acknowledged, and it provides for a composition useful as a shampoo or dishwashing composition comprising 55 parts anionic detergent, 20 parts nonionic detergent, 9 parts triethanolamine, 10 parts glycerine and 6 parts urea which is added to 250 parts by weight of water.
U.S. Pat. No. 4,001,123 discloses the use of urea or sugar treated N-higher alkyl-1,3-propylene diamines as fabric softening agents in compositions containing anionic detergents, nonionic detergents and alkaline builder salts which are heavy duty detergent compositions.
However, none of the above patents disclose a light duty detergent composition, based on anionic sulfonated surfactants or a mixture of such anionic and nonionic surfactants containing 1-10% by weight of a diacid salt of a low molecular weight aliphatic diamine having effective foamability and degreasing ability in both soft and hard water.
The Industrial and Engineering Chemistry article by Wilson, Vol. 27 (#8) 867-71 (1935) which discloses ethylene diamine dihydrochloride, the propylene diamine and piperazine eqivalents thereof, their synthesis and their reactions with acids to form diacid salts is included as part of this specification. However, there is no suggestion of the use of these diacid salts together with a detergent.